Oil and gas wells find new life with geothermal

There are an estimated 2.5 million abandoned oil and gas wells in the US alone

OLD oil and gas wells might soon be reborn as environmentally friendly geothermal power generators.

Geothermal energy holds promise as a low-carbon source of electricity because of its ubiquity – rock temperatures increase by between 25 and 50°C for every kilometre of depth due to heat from the Earth’s core. But as much as half the cost of geothermal power plants comes from drilling into the Earth.

Old oil and gas wells often plunge several kilometres deep to reach reserves. Refitting their shafts to circulate water could provide an easy way to extract this energy, says Xianbiao Bu and colleagues from the Chinese Academy of Sciences in Guangzho.